Propeller retention means



197 a... w. FOSTER PROPELLER RETENTION MEANS Filed May 16, 1966 W es WE Z Z gyll/l eg WWW/44 0 United States Patent O f 3,299,964 PROPELLER RETENTION MEANS Leslie W. Foster, Lake Bluff, Ill., assignor to Outboard Marine Corporation, Waukegan, 11]., a corporation of Delaware Filed May 16, 1966, Ser. No. 550,430 6 Claims. (Ci. 170-173) The invention relates to arrangements for retaining a marine propeller on a drive shaft. Although the disclosure herein is not limited to the construction disclosed in United State Patent 3,113,625, the invention herein disclosed constitutes, at least in part, an improvement over the propeller mounting arrangement shown in United States Patent 3,113,625.

In the past, it has been common practice to couple a propeller to a propeller shaft by a shear pin which can be readily removed to facilitate change in propellers or to facilitate shear pin replacement in the event of shear pin failure. Such shear pins were often hidden from view and were retained against unwanted loss by a propeller cap or nut which was designed to extend smoothly from the propeller hub and which extended around the ends of the shear pin to hide the shear pin and to prevent its loss. Various means such as a removable cotter pin or the like were employed to releasably retain the cap or nut on the propeller shaft.

One of the principal objects of the invention is to provide a propeller mounting arrangement wherein the formation of the end of the cap adjacent to the propeller is such as to receive the shear pin in rotatable driving engagement, thereby affording cap rotation concurrently with the rotation with the propeller by the propeller shaft. Thus, in the disclosed arrangement, the shear pin serves to rotatably drive the propeller as well as the propeller retaining cap, thereby decreasing resistance to fluid flow past the overall arrangement.

Another object of the invention is to provide a keeper which is capable of releasably locking a propeller retaining cap or nut to a propeller shaft and which cooperates with the end of the cap to prevent unwanted disassembly of the keeper from the end cap even when the keeper is not in locking position with respect to the propeller shaft.

Still another object of the invention is to provide a more economical and functionally advantageous arrangement for mounting and retaining a propeller on a propeller shaft.

Other objects and advantages of the invention will become known by reference to the following description and accompanying drawings in which:

FIGURE 1 is a fragmentary view of a marine propulsion unit embodying various of the features of the invention;

FIGURE 2 is a sectional view taken along line 2-2 of FIGURE 1, and;

FIGURE 3 is a sectional view taken along line 3--3 of FIGURE 1.

Shown in the drawings is a lower unit 11 of a marine propulsion device such as an outboard motor or stern drive unit. Supported by bearings 13 and 15 is a propeller shaft 17 which extends rearwardly from the lower unit and includes a transverse bore 19 and rearwardly of the boare 19, an end part 20 having an annular groove or recess 21.

Mounted on the propeller shaft 17 is a propeller 23 including a hub 25 having a sleeve 27 which receives the propeller shaft 17 and which includes a transverse aperture 29 adapted to mate with the transverse bore 19.

Removably located in the bore 19 and aperture 29 is a drive or shear pin 31. As can be readily seen, the shear pin 31 is designed so that its axial length is such as to 3,299,964 Patented Jan. 24, 1967 provide at least one end portion 32 extending radially outwardly from the sleeve 27. One of the shear pin end portions 32 is preferably tapered, as shown at 33, to assist in insertion of the shear pin 31 into the bore 19 and aperture 29.

Also mounted on the propeller shaft 17 rearwardly of the propeller 23 is a retainer or cap 41 which has an outer configuration affording smooth surface continuity from the propeller hub, thereby providing for streamlined flow of the Water past the propeller mounting arrangement. The cap 41 includes a blind bore 43 which extends rearwardly from the forward end of the cap, i.e., the end adjacent to the propeller 23, and which is adapted to receive the end part 20 of the propeller shaft 17. In addition, the forward end of the cap is provided with a counterbore 47 affording receipt of the adjacent end of the propeller sleeve 27. The forward end of the cap 41 also includes diametrically extending recess 49 adapted to receive the end portion 32 of the shear pin 31. The recesses are formed in part by wall surfaces 51 which are engaged by the sides of the shear pin end portions 32 to effect rotation of the cap 41 by the shear pin 31 concurrently with rotation of the propeller 23.

Various means or arrangements can be employed to retain the cap 41 on the propeller shaft 17 to prevent axial displacement of the cap 41 relative to the propeller shaft 17 and thereby also to retain the shear pin 31 in driving engagement with the recess 49 in the cap 41. In the disclosed construction, such means comprises the before mentioned annular groove 21 in the propeller 17 and a blind slot 53 which extends transversely in the cap 41 and is registerable with the annular groove 21, together with a keeper 54 which can take various forms, but which, in the preferred construction, is in the form of a spring clip 54 designed to engage the annular groove 21 and to thereby releasably prevent unwanted displacement from a position locking the cap 41 on the shaft 17.

More particularly, the slot 53 is defined in part by a first straight wall portion 55 offset from the center of the cap and which extends from a semi-cylindrical wall portion 57 at the blind end of the slot 53. Extending from the other end of the semi-cylindrical wall portion 57 is another Wall portion which is almost parallel to the Wall portion 55, which passes slightly to the far side of the cap center from the straight wall portion 55, and which includes two segments 59 and 61 extending in opposite sides of the bore 43. The slot outline is completed by a wall portion 63 which extends from the wall segment 61 and is angularly inclined so as to provide the slot with an enlarged opening or mouth 65.

Connecting with the slot is an anchoring recess 67 which is located in the wall portion 55 inwardly of the outer surface of the cap 41.

The spring clip 54, when relaxed, conforms, in part, to the shape of the slot 53, and includes a bight or segment 69 conforming to the shape of the semi-cylindrical wall portion 57, a segment 71 conforming to the shape of the wall segment 59 and a straight portion 73 conforming to the length of the straight wall portion 55 between the recess 67 and the semi-cylindrical wall portion 57. Extending from the straight portion is a tang 75 which is received in the recess 67 to anchor the keeper 54 in the slot 53.

Extending from the segment 71 is an arcuate gripping portion or segment 77 designed to be releasably received in the annular groove 21, together with a free portion 79 having a loop 81 which extends from the arcuate segment and is located in the mouth 65 of the slot 53 in position to be displaced, by a finger or tool, toward the straight portion 73 to release the arcuate portion 77 from engagement in the angular groove 21.

Thus, there is provided an arrangement wherein the keeper 54 is permanently connected to the cap 41 so as to avoid unintentional loss or misplacement. In addition, the keeper 54 is displaceable between a position in the annular groove 21 locking the cap 41 on the propeller shaft 17 and a position clear of the annular groove, thereby affording release of the propeller shaft 17 to facilitate cap removal.

Various of the features of the invention are set forth in the following claims.

What is claimed is:

1. The combination of a propeller shaft, a drive pin including a portion extending transversely of and from said shaft, a propeller retaining cap including a bore receiving the end of said propeller shaft, and a recess adapted for receiving said pin portion and extending transversely of and from said bore, said recess being defined, at least in part, by surfaces engaged by the sides of said pin portion, whereby said cap is rotatably driven by said shaft, and a keeper engaged with said cap and said shaft to prevent axial displacement of said cap relative to said shaft, thereby retaining said cap on said shaft and said pin in rotative driving engagement with said recess.

2. A combination in accordance with claim 1 wherein said cap includes wall means defining a transverse slot in which said keeper is anchored, and wherein said keeper includes a bite portion and an arcuate segment connected to said bite portion and displaceable within said slot relative to a position retaining said cap on said propeller.

3. A combination in accordance with claim 2 wherein said shaft includes an annular groove in registry with said slot and said keeper comprises a spring clip having a gripping portion engageable with said annular groove.

4. The combination of a propeller shaft having a transverse bore therein, a propeller on said shaft and in- 3 eluding a mounting sleeve having a transverse aperture in registry with said transverse bore, a shear pin extending in said transverse bore and aperture and including a portion projecting radially beyond said mounting sleeve, a

propeller retaining cap including a bore receiving the end of said propeller shaft,- a counter bore receiving the adjacent end of said mounting sleeve, and a recess extending transversely of and from said counter bore, open in the direction of said propeller, receiving'said pin portion, and including surfaces engaged with the sides of said pin portion, whereby said cap is rotatably driven by said shaft, and a keeper engaged with said cap and said shaft to prevent axial displacement of said cap relative to said shaft, thereby retaining said cap on said shaft and said pin in said recess.

5. A combination in accordance with claim 4 wherein said cap includes wall means defining a transverse slot in which said keeper is anchored, and wherein said keeper includes a bite portion and an arcuate segment connected to said bite portion and displaceable Within said slot relative to a position retaining said cap on said propeller.

6. A combination in accordance with claim 5 wherein said shaft includes an annular groove in registry with said slot and said keeper comprises a spring clip having a gripping portion engageable with said annular groove.

References Cited by the Examiner UNITED STATES PATENTS 2,564,605 8/1951 Martin 170-173 X 3,113,625 12/1963 Conover 170-16054 X 3,144,909 8/1964 Hart et a1. 170-177 FOREIGN PATENTS 402,362 9/ 1924 Germany. 736,719 9/1955 Great Britain.

MARTIN P. SCHWADRON, Primary Examiner.

E. A. POWELL, Assistarvt Examiner. 

1. THE COMBINATION OF A PROPELLER SHAFT, A DRIVE PIN INCLUDING A PORTION EXTENDING TRANSVERSELY OF AND FROM SAID SHAFT, A PROPELLER RETAINING CAP INCLUDING A BORE RECEIVING THE END OF SAID PROPELLER SHAFT, AND A RECESS ADAPTED FOR RECEIVING SAID PIN PORTION AND EXTENDING TRANSVERSELY OF AND FROM SAID BORE, SAID RECESS BEING DEFINED, AT LEAST IN PART, BY SURFACES ENGAGED BY THE SIDES OF SAID PIN PORTION, WHEREBY SAID CAP IS ROTATABLY DRIVEN BY SAID SHAFT, AND A KEEPER ENGAGED WITH SAID CAP AND SAID SHAFT TO PREVENT AXIAL DISPLACEMENT OF SAID CAP RELATIVE TO SAID SHAFT, THEREBY RETAINING SAID CAP ON SAID SHAFT AND SAID PIN IN ROTATIVE DRIVING ENGAGEMENT WITH SAID RECESS. 